Too obvious to be stated, once he left the flat, Marie and everything connected with her ceased to exist in Gavin’s world.
He went early to work and stayed late.
It wasn’t until he was entering the flat, Marie returned to existence.
If Marie was having an episode and didn’t prepare his dinner, he cooked for himself as if he lived alone. This taught Marie that ‘denying’ Gavin dinner did not work.
If there was a bill to be paid or a situation had arisen, she had to tell him.
After eating, he would take his dishes to the sink. She would, if ‘normal’ say; “Leave them, I’ll wash.” If not, he’d wash them.
Then go into the bedroom and his computer. When Marie arrived, she’d be environment.
As long as he was withdrawn, locked into himself, ignoring her, there was peace.